OKLAHOMA CITY (AP) -- A granite monument of the Ten Commandments that has sparked controversy since its installation on the Oklahoma Capitol grounds was being removed late Monday and will be transported to a private conservative think tank for storage.

A contractor the state hired began removing the monument shortly after 10:30 p.m. The works comes after the Oklahoma Supreme Court's decision in June that the display violates a state constitutional prohibition on the use of public property to support "any sect, church, denomination or system of religion."

The state is paying the contractor about $4,700 to remove the monument and take it to the Oklahoma Council of Public Affairs' offices a few blocks away, Office of Management and Enterprise Services spokesman John Estus said.

The Oklahoma Highway Patrol had increased security around the monument earlier Monday, and barriers were erected to keep visitors from getting close to it. Estus said the decision to remove the monument under the cover of darkness was made to avoid disturbing workers at the Capitol and to keep protesters from demonstrating while heavy equipment was being used to detach the two-ton monument from its base.

"We wanted it to be done as quickly and efficiently as possible, and doing it at night gave us the best opportunity to do that," Estus said. "The Highway Patrol was also very concerned that having it in the middle of the day could lead to having demonstrations of some kind."

Originally authorized by the Republican-controlled Legislature in 2009, the privately funded monument has been a lightning rod for controversy since it was erected in 2012, prompting a lawsuit from Bruce Prescott, a Baptist minister from Norman who complained it violated the state constitution.

"Frankly, I'm glad we finally got the governor and attorney general to agree to let the monument be moved to private property, which is where I believe it's most appropriate," Prescott said Monday. "I'm not opposed to the Ten Commandments. The first sermon I ever preached was on the Ten Commandments. I'm just opposed to it being on public property."

Its placement at the Capitol prompted requests from several groups to have their own monuments installed, including a satanic church in New York that wanted to erect a 7-foot-tall statue that depicts Satan as Baphomet, a goat-headed figure with horns, wings and a long beard. A Hindu leader in Nevada, an animal rights group and the satirical Church of the Flying Spaghetti Monster also made requests.

The original monument was smashed into pieces last year when someone drove a car across the Capitol lawn and crashed into it. A 29-year-old man who was arrested the next day was admitted to a hospital for mental health treatment, and formal charges were never filed. A new monument was erected in January.

Former state Rep. Mike Reynolds, a Republican who voted to authorize the monument, was one of just a handful of supporters who watched as the monument was removed Monday night.

"This is a historical event," Reynolds said. "Now we know we have to change the Constitution. It would be good to get rid of some of the Supreme Court justices, too."

Several conservative legislators have promised to introduce a resolution when the Legislature convenes in February to send to a public vote an amendment that would remove the article of the constitution that prevents the use of public money or property for religious purposes.